<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
<script>
    for(var b=0;b<=31;++b){
        var w=31-b;
        var r=28-b;
        if ((r+w==25)){

            document.write('红球：' + r + '，白球：' + w +'，黑球：' + b);
        }




    }



</script>

</body>
</html>